[PATCHv2 2/4] fwu: move meta-data management in core
jassisinghbrar at gmail.com
jassisinghbrar at gmail.com
Sat Dec 3 04:17:02 CET 2022
From: Jassi Brar <jaswinder.singh at linaro.org>
Instead of each i/f having to implement their own meta-data verification
and storage, move the logic in common code. This simplifies the i/f code
much simpler and compact.
Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
---
drivers/fwu-mdata/fwu-mdata-uclass.c | 34 +++++++
include/fwu.h | 41 ++++++++
lib/fwu_updates/fwu.c | 143 ++++++++++++++++++++++++++-
3 files changed, 214 insertions(+), 4 deletions(-)
diff --git a/drivers/fwu-mdata/fwu-mdata-uclass.c b/drivers/fwu-mdata/fwu-mdata-uclass.c
index b477e9603f..e03773c584 100644
--- a/drivers/fwu-mdata/fwu-mdata-uclass.c
+++ b/drivers/fwu-mdata/fwu-mdata-uclass.c
@@ -16,6 +16,40 @@
#include <linux/types.h>
#include <u-boot/crc.h>
+/**
+ * fwu_read_mdata() - Wrapper around fwu_mdata_ops.read_mdata()
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_read_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary)
+{
+ const struct fwu_mdata_ops *ops = device_get_ops(dev);
+
+ if (!ops->read_mdata) {
+ log_debug("read_mdata() method not defined\n");
+ return -ENOSYS;
+ }
+
+ return ops->read_mdata(dev, mdata, primary);
+}
+
+/**
+ * fwu_write_mdata() - Wrapper around fwu_mdata_ops.write_mdata()
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_write_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary)
+{
+ const struct fwu_mdata_ops *ops = device_get_ops(dev);
+
+ if (!ops->write_mdata) {
+ log_debug("write_mdata() method not defined\n");
+ return -ENOSYS;
+ }
+
+ return ops->write_mdata(dev, mdata, primary);
+}
+
/**
* fwu_get_mdata_part_num() - Get the FWU metadata partition numbers
* @dev: FWU metadata device
diff --git a/include/fwu.h b/include/fwu.h
index 0919ced812..1a700c9e6a 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -24,6 +24,26 @@ struct fwu_mdata_gpt_blk_priv {
* @update_mdata() - Update the FWU metadata copy
*/
struct fwu_mdata_ops {
+ /**
+ * read_mdata() - Populate the asked FWU metadata copy
+ * @dev: FWU metadata device
+ * @mdata: Copy of the FWU metadata
+ * @primary: If primary or secondary copy of meta-data is to be read
+ *
+ * Return: 0 if OK, -ve on error
+ */
+ int (*read_mdata)(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
+
+ /**
+ * write_mdata() - Write the given FWU metadata copy
+ * @dev: FWU metadata device
+ * @mdata: Copy of the FWU metadata
+ * @primary: If primary or secondary copy of meta-data is to be written
+ *
+ * Return: 0 if OK, -ve on error
+ */
+ int (*write_mdata)(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
+
/**
* check_mdata() - Check if the FWU metadata is valid
* @dev: FWU device
@@ -126,6 +146,27 @@ struct fwu_mdata_ops {
EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
+/**
+ * fwu_read_mdata() - Wrapper around fwu_mdata_ops.read_mdata()
+ */
+int fwu_read_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
+
+/**
+ * fwu_write_mdata() - Wrapper around fwu_mdata_ops.write_mdata()
+ */
+int fwu_write_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary);
+
+/**
+ * fwu_get_verified_mdata() - Read, verify and return the FWU metadata
+ *
+ * Read both the metadata copies from the storage media, verify their checksum,
+ * and ascertain that both copies match. If one of the copies has gone bad,
+ * restore it from the good copy.
+ *
+ * Return: 0 if OK, -ve on error
+*/
+int fwu_get_verified_mdata(struct fwu_mdata *mdata);
+
/**
* fwu_check_mdata_validity() - Check for validity of the FWU metadata copies
*
diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
index 5313d07302..f17bd8ea63 100644
--- a/lib/fwu_updates/fwu.c
+++ b/lib/fwu_updates/fwu.c
@@ -15,13 +15,13 @@
#include <linux/errno.h>
#include <linux/types.h>
+#include <u-boot/crc.h>
+
+static struct fwu_mdata g_mdata; /* = {0} makes uninit crc32 always invalid */
+static struct udevice *g_dev;
static u8 in_trial;
static u8 boottime_check;
-#include <linux/errno.h>
-#include <linux/types.h>
-#include <u-boot/crc.h>
-
enum {
IMAGE_ACCEPT_SET = 1,
IMAGE_ACCEPT_CLEAR,
@@ -161,6 +161,141 @@ static int fwu_get_image_type_id(u8 *image_index, efi_guid_t *image_type_id)
return -ENOENT;
}
+/**
+ * fwu_sync_mdata() - Update given meta-data partition(s) with the copy provided
+ * @mdata: FWU metadata structure
+ * @part: Bitmask of FWU metadata partitions to be written to
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static int fwu_sync_mdata(struct fwu_mdata *mdata, int part)
+{
+ void *buf = &mdata->version;
+ int err = 0;
+
+ /*
+ * Calculate the crc32 for the updated FWU metadata
+ * and put the updated value in the FWU metadata crc32
+ * field
+ */
+ mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
+
+ if (part & PRIMARY_PART)
+ err = fwu_write_mdata(g_dev, mdata, true);
+
+ if (err) {
+ log_err("Unable to write primary mdata\n");
+ return err;
+ }
+
+ if (part & SECONDARY_PART)
+ err = fwu_write_mdata(g_dev, mdata, false);
+
+ if (err) {
+ log_err("Unable to write secondary mdata\n");
+ return err;
+ }
+
+ /* update the cached copy of meta-data */
+ memcpy(&g_mdata, mdata, sizeof(struct fwu_mdata));
+
+ return 0;
+}
+
+static inline int mdata_crc_check(struct fwu_mdata *mdata)
+{
+ void *buf = &mdata->version;
+ u32 calc_crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));
+
+ return calc_crc32 == mdata->crc32 ? 0 : -EINVAL;
+}
+
+/**
+ * fwu_get_verified_mdata() - Read, verify and return the FWU metadata
+ *
+ * Read both the metadata copies from the storage media, verify their checksum,
+ * and ascertain that both copies match. If one of the copies has gone bad,
+ * restore it from the good copy.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_get_verified_mdata(struct fwu_mdata *mdata)
+{
+ int err;
+ bool pri_ok, sec_ok;
+ struct fwu_mdata s, *p_mdata, *s_mdata;
+
+ p_mdata = &g_mdata;
+ s_mdata = &s;
+
+ /* if mdata already read and ready */
+ err = mdata_crc_check(p_mdata);
+ if (!err) {
+ if (mdata)
+ memcpy(mdata, p_mdata, sizeof(struct fwu_mdata));
+ return 0;
+ }
+ /* else read, verify and, if needed, fix mdata */
+
+ pri_ok = false;
+ err = fwu_read_mdata(g_dev, p_mdata, true);
+ if (!err) {
+ err = mdata_crc_check(p_mdata);
+ if (!err)
+ pri_ok = true;
+ else
+ log_debug("primary mdata: crc32 failed\n");
+ }
+
+ sec_ok = false;
+ err = fwu_read_mdata(g_dev, s_mdata, false);
+ if (!err) {
+ err = mdata_crc_check(s_mdata);
+ if (!err)
+ sec_ok = true;
+ else
+ log_debug("secondary mdata: crc32 failed\n");
+ }
+
+ if (pri_ok && sec_ok) {
+ /*
+ * Before returning, check that both the
+ * FWU metadata copies are the same.
+ */
+ err = memcmp(p_mdata, s_mdata, sizeof(struct fwu_mdata));
+ if (!err)
+ return 0;
+
+ /*
+ * If not, populate the secondary partition from the
+ * primary partition copy.
+ */
+ log_info("Both FWU metadata copies are valid but do not match.");
+ log_info(" Restoring the secondary partition from the primary\n");
+ sec_ok = false;
+ }
+
+ if (!pri_ok) {
+ memcpy(p_mdata, s_mdata, sizeof(struct fwu_mdata));
+ err = fwu_sync_mdata(p_mdata, PRIMARY_PART);
+ if (err)
+ goto exit_fix;
+ }
+
+ if (!sec_ok) {
+ memcpy(s_mdata, p_mdata, sizeof(struct fwu_mdata));
+ err = fwu_sync_mdata(s_mdata, SECONDARY_PART);
+ if (err)
+ goto exit_fix;
+ }
+
+exit_fix:
+ if (err)
+ log_debug("mdata saving : crc32 failed\n");
+
+ return err;
+}
+
/**
* fwu_verify_mdata() - Verify the FWU metadata
* @mdata: FWU metadata structure
--
2.34.1
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